.header{
    background-color: black;
    width: 100%;
    height: 60px;
    position:fixed;
    left:0;
    top:0;
    z-index: 99999;
    box-shadow: 0 0 10px dimgrey;

}

.header .logo {
    line-height: 1;
    padding-left:100px;
    padding-top: 10px;
    padding-bottom: 10px;
    font-size: 30px;
    display: inline-block;
    margin-bottom: 10px;
    color:white;
    float: left;
}

.header .navbar{/*设置导航栏的框框*/
    margin-top: 0;
    margin-left: 20px;
    padding: 0px;/*将框框的padding设置为零，不然会导致框框里的内容与框边缘有间隔*/
    float: left;
}

.header .navbar li{
    list-style-type: none;/* 去掉li前的点 */
    float: left;/*将li设置成做浮动，变为联动*/
}

.header .navbar li a{
    -webkit-margin-end: 0;
    -webkit-margin-start: 0;
    display: block;/*将a变成块状*/
    width: 80px;/*设置块的宽度*/
    height: 60px;/*设置块的长度*/
    font-family: Microsoft Yahei;
    line-height: 50px;/*设置字体在块中的高度*/
    margin: 2px 0px;/*块里的高宽通过margin设置*/
    color: #fff;
    text-align: center;/*字体居中*/
    text-decoration: none;/*去掉下划线*/
    font-size: 17px;
}


.header .navbar a:hover{
    background-color: #454545;
    height: 60px;
}




.dropbtn {
    background-color: black;
    color: white;
    border: none;
    cursor: pointer;
}

.dropdown {
    position: relative;
    display: inline-block;
    width: 80px;/*设置块的宽度*/
    height: 60px;/*设置块的长度*/
    font-family: Microsoft Yahei;
    line-height: 50px;/*设置字体在块中的高度*/
    margin: 2px 0px;/*块里的高宽通过margin设置*/
    text-align: center;/*字体居中*/
    font-size: 17px;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #f9f9f9;
    min-width: 100px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
}

.header .navbar .dropdown-content a {
    color: black;
    padding: 12px;
    text-decoration: none;
    display: block;
    line-height: 35px;
}

.header .navbar .dropdown-content a:hover {background-color: #454545;color:white}

.dropdown:hover .dropdown-content {
    display: block;
}

.dropdown:hover .dropbtn {
    background-color: #454545;
    height: 60px;
}
























.mo-header{
    background-color: black;
    width: 100%;
    height: 60px;
    position:fixed;
    left:0;
    top:0;
    z-index: 99999;
    text-align: center;
    box-shadow: 0 0 10px dimgrey;
}




.mo-logo {
    line-height: 1;
    font-size: 30px;
    display: inline-block;
    margin: 15px;
    color:white;
    float: left;
}





@media screen and (min-width: 769px){
    .header{
        display: block;
    }
    .mo-header{
        display: none;
    }
}

@media screen and (max-width: 767px){
    .header{
        display: none;
    }
    .mo-header{
        display: block;
    }
}


@media screen and (width: 768px) and (orientation: portrait){
    .header{
        display: none;
    }
    .mo-header{
        display: block;
    }
}

@media screen and (width: 768px) and (orientation: landscape){
    .header{
        display: block;
    }
    .mo-header{
        display: none;
    }
}



